In order to be able to permanently fasten thermally impacted pipes on a support, it is common to mount the respective pipe on the support using a fixed bearing on the one hand, and a movable bearing on the other, thereby allowing the length of the pipe to change relative to the support without inadmissibly high stresses occurring between pipe and support. Movable bearings of this kind may be realised using so-called sliding seats, where the pipe sits in a locating opening formed in the respective support, in such a way that the pipe is axially displaceable relative to its longitudinal axis.
Thermally impacted pipes, which are mounted on a structural support part by means of a sliding seat, are employed in many areas of the art, in particular in those areas where hot or cold fluids are conveyed in pipes. This problem occurs, for example, in heating systems, cooling systems and exhaust gas systems. Exhaust gas systems are found in heating devices and in combustion engines, preferably in motor vehicles. For example, an exhaust gas treatment facility may include at least one pipe which is mounted in a housing of the exhaust gas treatment facility with the aid of such a sliding seat. An exhaust gas treatment facility may, for example, be a particle filter, a converter or a sound absorber or any combination of such facilities.
A conventional sliding seat may have a certain amount of radial play between the pipe and the respective locating opening in order to allow the pipe to be displaced in the seat more easily. This is unfavourable for applications which require a certain gas-tightness because it is, in principle, possible for a gas exchange to take place through the sliding seat. Tighter environmental protection standards require that on exhaust gas systems, in particular, an escape of exhaust gas into the environment, for example through a sliding seat, must be avoided.
Furthermore conventional sliding seats, in principle, suffer from the problem of a comparatively high mechanical load on the pipe or the respective structural support part within the sliding seat. Mechanical loads are connected with wear and may lead to the development of background noise.